JSON Pointer Evaluator
Evaluate a JSON Pointer (RFC 6901) against a JSON document and see the exact value it resolves to — useful for testing pointer expressions before wiring them into code.
Input
RFC 6901 syntax: starts with '/', escape '~' as '~0' and '/' as '~1'. Empty string means the whole document.
Output
Guides
The JSON Pointer Evaluator resolves a JSON Pointer expression against a JSON document and shows you exactly what value it points to. It's the fastest way to test a pointer expression before wiring it into JSON.parse + manual lookups, a JSON Patch operation, or an OpenAPI $ref.
What it does
Paste a JSON document and a pointer expression, and the tool walks the document one reference token at a time, returning the resolved value as formatted JSON. If the pointer can't be resolved — a missing key, an out-of-bounds array index, or a malformed token — it explains exactly why instead of failing silently.
How to use it
- Paste your JSON document into the JSON document field.
- Enter a pointer in the JSON Pointer field, such as
/user/roles/0. - Read the resolved value in the output — it updates as you type.
JSON Pointer syntax
A pointer is a string of /-separated reference tokens. Each token names an object key or, for arrays, a zero-based index:
""(empty string) refers to the whole document./user/idwalks intouser, thenid./user/roles/0walks intouser, thenroles, then the first array element.- A literal
~in a key is escaped as~0, and a literal/in a key is escaped as~1(so a key literally nameda/bis addressed as/a~1b). /user/roles/-is valid syntax reserved for appending to an array in JSON Patch, but has no value to read — evaluating it returns an error here.
Common uses
- API developers testing
$ref/pointer expressions used in OpenAPI or JSON Schema documents. - Backend engineers verifying a JSON Patch (RFC 6902)
pathbefore applying it. - Anyone debugging a deeply nested JSON payload who wants to confirm a path resolves to the value they expect.
Is my data private?
Yes. Evaluation happens entirely in your browser — your JSON is never uploaded to a server.
Use it from code
From 3 credits per callREST API
curl -X POST https://api.iotools.cloud/v1/tool/json-pointer-evaluator \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"json": "{\"user\":{\"id\":1,\"roles\":[\"admin\",\"editor\"]},\"act…",
"pointer": "/user/roles/0"
}'Swap in your own key from your account. The tool's fields are the body — no wrapper.
Ask an AI agent
Use the IOTools `json-pointer-evaluator` tool (JSON Pointer Evaluator) on this input:
YOUR_INPUT_HEREPaste this at any agent connected to the IOTools MCP server, then add your input.